Current Status of Stellar Evolutionary Models for AGB Stars

Asymptotic giant branch (AGB) stars play an important role in determining the chemical and evolutionary properties of galaxies. Stellar evolutionary models of AGB stars provide a good qualitative match to observations, although detailed comparisons reveal problems with our understanding of important physical processes such as mixing. The main stellar modelling uncertainties include our inability to accurately calculate convection in stars, and the rates of mass loss during the AGB. The inability to model convection is especially problematic during the AGB owing to the occurrence of the third dredge-up and hot bottom burning, while mass loss will limit the number of mixing episodes. In these proceedings the current status of evolutionary models of AGB stars is reviewed, along with a discussion of how convection in particular affects AGB models. Finally, we discuss how AGB stars in the Magellanic Cloud may be used as probes of AGB evolution and nucleosynthesis.